Copper chelating resins

Theory. Conventional anion and cation exchange resins appear to be of limited use for concentrating trace metals from saline solutions such as sea water. The introduction of chelating resins, particularly those based on iminodiacetic acid, makes it possible to concentrate trace metals from brine solutions and separate them from the major components of the solution. Thus the elements cadmium, copper, cobalt, nickel and zinc are selectively retained by the resin Chelex-100 and can be recovered subsequently for determination by atomic absorption spectrophotometry.45 To enhance the sensitivity of the AAS procedure the eluate is evaporated to dryness and the residue dissolved in 90 per cent aqueous acetone. The use of the chelating resin offers the advantage over concentration by solvent extraction that, in principle, there is no limit to the volume of sample which can be used. 

Beck et al. [61] used flow injection magnetic sector ICP-MS to determine cadmium, copper, nickel, zinc, and manganese in estuarine waters. The online preconcentration system used Toyopearl A-T Chelate 650 H as chelating resin, and was validated for an alkaline water standard reference material (SLEW-2). 

Menoud et al. (1998) studied the adsoiption of copper from aqueous solutions by using the chelating resin Chelamine. The resin used is spherical, with an average diameter of 0.305 mm, swollen particle density of 158.4 kg/m3 (dry) and hydraulic particle density (wet density) of 1064 kg/m3. 

Lohan, M.C., A.M. Aguilar-Islas, R.R Franks, and K.W. Bruland. 2005. Determination of iron and copper in seawater at pH 1.7 with a new commercially available chelating resin, NTA Superflow. Anal. Chim. Acta 530 121-129. 

The A -Boc-protected diamino acids are prepared via the copper(II) complexes of lysine or ornithine,b l or by using suitable N -protected derivatives obtained by the benzylidene route under conventional Schotten-Baumann conditionsJ l Since previous reports differ in yields and are not completely reproducible, the procedures have been optimizedJ l Thereby, the chelating resin Chelex 100 can efficiently be used for decomposition of the Cu[Lys(Boc)]2 complex. However, as this resin is expensive, an alternative procedure has been proposed for large-scale synthesis that is based on the use of the inexpensive quinolin-8-ol to quantitatively remove the copper(II) ions.P l The resulting H-Lys(Boc)-OH intermediate is then converted into the desired N -protected form by the classical procedures reported in Section 2.1.1. For cleavage of the A -Boc protection by various acidic reaction conditions, see Section 2.1.1.1.3.1.3. 

Ligand exchange chromatography on a copper-loaded chelating resin 238... 

Liu, Y. Yu, S. Copper(II)-iminodiacetic acid chelating resin as a stationary phase in the immobihzed metal ion affinity chromatography of some aromatic amines. J. Chromatogr. 1990, 515, 169-173. 

Lee, D.-Y., and Zheng, H.-C. (1994). Simultaneous extraction of soil phytoavailable cadmium, copper, and lead by chelating resin membrane. Plant Soil 164, 19-23... 

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